Organic light emitting diodes (OLED) refer to a structure in which a functional organic material layer is inserted between an anode and a cathode, wherein an exciton having high energy can be created by recombination of a hole injected into the cathode and an electron injected into the anode. The created exciton may move in a ground state, thereby emitting light within a specific wavelength band. The organic light emitting diodes have various merits such as self-luminance, fast response, wide viewing angle, ultra-thinness, high definition and durability.
However, organic light emitting diodes have problems in that, due to moisture or oxygen flowing from outside or outgases generated inside or outside of the light emitting diodes despite sealing, thus organic materials and/or electrode materials can be oxidized, causing deterioration in the performance and lifespan thereof. In order to overcome such problems, some methods have been proposed, such as coating with a photocurable sealing agent, attachment of a transparent or opaque moisture absorbent, or provision of frits to a substrate on which an organic light emitting diode is formed.
For instance, Korean Publication No. 2006-0084978A has disclosed an encapsulated structure of organic light emitting diode devices, which includes a protective member for sealing formed by any one of moisture penetration inhibiting materials among silicone compounds and polymer resins.